Sensitivity Of MRI Research Articles

Sensitivity of unconstrained quantitative magnetization transfer MRI to amyloid burden in preclinical Alzheimer’s disease

Abstract Magnetization transfer MRI is sensitive to semisolid macromolecules, including amyloid beta, and has previously been used to discriminate Alzheimer’s disease (AD) patients from controls. Here, we fit an unconstrained 2-pool quantitative MT (qMT) model, that is, without constraints on the longitudinal relaxation rate R1s of semisolids, and investigate the sensitivity of the estimated parameters to amyloid accumulation in preclinical participants. We scanned 15 cognitively normal volunteers, of which 9 were amyloid positive by [18F]florbetaben PET. A 12 min hybrid-state qMT scan with an effective resolution of 1.24 mm isotropic and whole-brain coverage was acquired to estimate the unconstrained 2-pool qMT parameters. Group comparisons and correlations with florbetaben PET standardized uptake value ratios were analyzed at the lobar level. We find that the exchange rate and semisolid pool’s R1s were sensitive to the amyloid concentration, while morphometric measures of cortical thickness derived from structural MRI were not. Changes in the exchange rate are consistent with previous reports in clinical AD, while changes in R1s have not been reported previously as its value is typically constrained in the literature. Our results demonstrate that qMT MRI may be a promising surrogate marker of amyloid beta without the need for contrast agents or radiotracers.

Clinical diagnostic study of Ramp lesion of medial meniscus based on knee MRI at 90° flexed position

To evaluate the clinical diagnostic value of knee MRI at 90° flexed position for Ramp lesions of medial meniscus. A total of 228 patients with knee pain as the main complaint who were admitted between September 2021 and September 2023 was selected as the research subjects, of which 51 patients met the selection criteria and were enrolled in the study. There were 31 males and 20 females with an average age of 38.6 years (range, 15-67 years). Body mass index was 17.2-28.7 kg/m 2 (mean, 23.9 kg/m 2). There were 25 cases of left knee and 36 cases of right knee. The time from injury to admission was 0.1-14.3 weeks (mean, 2.1 weeks). Preoperative knee MRI at fully extended position (knee extension position) and 90° flexed position (knee flexion position) were performed to determine the presence of irregular signs at the posterior edge of the medial meniscus, and PHMM fluid high signal [i.e. complete fluid filling between the posterior horn of the medial meniscus (PHMM) and the capsule margin]. Findings obtained under arthroscopy served as the "gold standard" to analyze the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of MRI at knee extension and flexion positions for the two specific signs of Ramp lesion. Twenty-one patients (41.2%) were diagnosed with Ramp lesions by using arthroscopy, including 1 case of Thaunat type Ⅰ, 2 cases of type Ⅱ, 6 cases of type Ⅲ, 7 cases of type Ⅳ, and 5 cases of type Ⅴ. The positive rates of irregular signs at the posterior edge of the medial meniscus on MRI at knee extension and flexion positions were significantly different from the diagnosis of Ramp injury under arthroscopy ( P<0.05). The sensitivity, specificity, accuracy, PPV, and NPV of MRI in the diagnosis of irregular signs were 76.1%, 60.0%, 66.7%, 57.1%, and 78.3% respectively at knee extension position, and 85.7%, 73.3%, 78.4%, 69.2%, and 88.0% respectively at knee flexion position. The positive rates of PHMM fluid high signal on MRI at knee extension and flexion positions were significantly different from the diagnosis of Ramp injury under arthroscopy ( P<0.05). The sensitivity, specificity, accuracy, PPV, and NPV of MRI in diagnosing PHMM fluid high signal were 38.1%, 100%, 74.5%, 100%, and 69.8% respectively at knee extension position, and 85.7%, 100%, 94.1%, 100%, and 90.9% respectively at knee flexion position. Knee MRI at 90° flexed position improves the diagnostic performance of the detection of medial meniscal Ramp lesions compared with MRI at fully extended position.

HPB SO07 - Update to the role of staging laparoscopies in stratifying patients by operability in perihilar cholangiocarcinoma

Abstract Background Radical resection of perihilar cholangiocarcinoma (pCCA) is only an option for the minority presenting at an early stage. Sensitivity of radiological imaging to detect liver and peritoneal metastases is insufficient. Our published 2017 cohort study demonstrated over a quarter of patients with no radiologically detectable metastatic disease were subsequently found to have unresectable disease by staging laparoscopy. However, less than 3% of these patients had preoperative PET-CT, which is now strongly recommended in new national guidance.Advances in CT and MRI sensitivity and increased PET-CT use demanded a reassessment of the need for staging laparoscopy in diagnostic assessment of resectability. Method All patients referred to a tertiary UK hepatobiliary centre with a new diagnosis of radiologically suspected or biopsy-proven pCCA from January 2020 to January 2024 were included (n=305). Patients were identified through a prospectively maintained cancer database. Electronic health records were interrogated for demographic data, preoperative radiological imaging, and details related to operative procedures. Those referred with, or subsequently found to have, any of the following conditions were excluded: recurrent pCCA, intrahepatic or distal cholangiocarcinoma, gallbladder cancer or benign hepatobiliary disease. Results All patients underwent CT chest, abdomen and pelvis. 194 (64%) received contrast MRI liver or MRCP. Based on these, 242 (79%) had locally advanced or metastatic cancer, comorbidities precluding resection or otherwise declined surgery. PET-CT was employed to investigate all remaining 63 patients, which discovered metastatic disease in 16 patients (25%). 47 patients proceeded to staging laparoscopy. This yielded metastatic or locally advanced disease in five patients (11%); a near-statistically significant drop compared to our previously published yield of 27.2% (p=0.060). Two (5%) had open-and-close laparotomies for irresectable disease, compared to 16 of 114 (14%) in our 2017 publication (p=0.14). Conclusion Technological advances of CT and MRI and use of PET-CT have vastly improved detection of irresectable pCCA. This study reinforces the merits of PET-CT in identifying occult disease, and we would encourage units that undertake these resections to utilise this imaging modality prior to undertaking staging laparoscopy. Nevertheless, peritoneal spread remains challenging to exclude radiologically, and diagnostic laparoscopy endures as a vital tool in the prevention of open-and-close laparotomies.

Age-related alterations in human cortical microstructure across the lifespan: Insights from high-gradient diffusion MRI.

The human brain undergoes age-related microstructural alterations across the lifespan. Soma and Neurite Density Imaging (SANDI), a novel biophysical model of diffusion MRI, provides estimates of cell body (soma) radius and density, and neurite density in gray matter. The goal of this cross-sectional study was to assess the sensitivity of high-gradient diffusion MRI toward age-related alterations in cortical microstructure across the adult lifespan using SANDI. Seventy-two cognitively unimpaired healthy subjects (ages 19-85 years; 40 females) were scanned on the 3T Connectome MRI scanner with a maximum gradient strength of 300mT/m using a multi-shell diffusion MRI protocol incorporating 8 b-values and diffusion time of 19 ms. Intra-soma signal fraction obtained from SANDI model-fitting to the data was strongly correlated with age in all major cortical lobes (r = -0.69 to -0.60, FDR-p < 0.001). Intra-soma signal fraction (r = 0.48-0.63, FDR-p < 0.001) and soma radius (r = 0.28-0.40, FDR-p < 0.04) were significantly correlated with cortical volume in the prefrontal cortex, frontal, parietal, and temporal lobes. The strength of the relationship between SANDI metrics and age was greater than or comparable to the relationship between cortical volume and age across the cortical regions, particularly in the occipital lobe and anterior cingulate gyrus. In contrast to the SANDI metrics, all associations between diffusion tensor imaging (DTI) and diffusion kurtosis imaging metrics and age were low to moderate. These results suggest that high-gradient diffusion MRI may be more sensitive to underlying substrates of neurodegeneration in the aging brain than DTI and traditional macroscopic measures of neurodegeneration such as cortical volume and thickness.

Ovarian-adnexal reporting and data system MRI scoring: diagnostic accuracy, interobserver agreement, and applicability to machine learning

Abstract Objectives To evaluate the interobserver agreement and diagnostic accuracy of ovarian-adnexal reporting and data system magnetic resonance imaging (O-RADS MRI) and applicability to machine learning. Methods Dynamic contrast-enhanced pelvic MRI examinations of 471 lesions were retrospectively analysed and assessed by 3 radiologists according to O-RADS MRI criteria. Radiomic data were extracted from T2 and post-contrast fat-suppressed T1-weighted images. Using these data, an artificial neural network (ANN), support vector machine, random forest, and naive Bayes models were constructed. Results Among all readers, the lowest agreement was found for the O-RADS 4 group (kappa: 0.669; 95% confidence interval [CI] 0.634-0.733), followed by the O-RADS 5 group (kappa: 0.709; 95% CI 0.678-0.754). O-RADS 4 predicted a malignancy with an area under the curve (AUC) value of 74.3% (95% CI 0.701-0.782), and O-RADS 5 with an AUC of 95.5% (95% CI 0.932-0.972) (P &amp;lt; .001). Among the machine learning models, ANN achieved the highest success, distinguishing O-RADS groups with an AUC of 0.948, a precision of 0.861, and a recall of 0.824. Conclusion The interobserver agreement and diagnostic sensitivity of the O-RADS MRI in assigning O-RADS 4-5 were not perfect, indicating a need for structural improvement. Integrating artificial intelligence into MRI protocols may enhance their performance. Advances in knowledge Machine learning can achieve high accuracy in the correct classification of O-RADS MRI. Malignancy prediction rates were 74% for O-RADS 4 and 95% for O-RADS 5.

Large improvement in RF magnetic fields and imaging SNR with whole-head high-permittivity slurry helmet for human-brain MRI applications at 7 T.

To optimize the design and demonstrate the integration of a helmet-shaped container filled with a high-permittivity material (HPM) slurry with RF head coil arrays to improveRF coil sensitivity and SNR for human-brain proton MRI. RF reception magneticfields ( ) of a 32-channel receive-only coil array with various geometries and permittivity values of HPM slurry helmet are calculated with electromagnetic simulation at 7 T. A 16-channel transmit-only coil array, a 32-channel receive-only coil array, and a 2-piece HPM slurry helmet were constructed and assembled. RF transmission magnetic field ( ), , and MRI SNR maps from the entire human brain were measured and compared. Simulations showed that averaged improvement with the HPM slurry helmet increased from 57% to 87% as the relative permittivity (εr) of HPM slurry increased from 110 to 210. In vivo experiments showed that the average improvement over the human brain was 14.5% with the two-piece HPM slurry (εr ≈ 170) helmet, and the average and SNR were improved 63% and 34%, respectively, because the MRI noise level was increased by the lossy HPM. The RF coil sensitivity and MRI SNR were largely improved with the two-piece HPM slurry helmet demonstrated by both electromagnetic simulations and in vivo human head experiments at 7 T. The findings demonstrate that incorporating an easily producible HPM slurry helmet into the RF coil array significantly enhances human-brain MRI SNRhomogeneity and quality at ultrahigh field. Greater SNR improvement is anticipated using the less lossy HPM and optimal design.

Diagnostic Accuracy of MRI for Detecting Nerve Injury in Brachial Plexus Birth Injury.

To determine the diagnostic accuracy of MRI for diagnosing nerve injury in brachial plexus birth injury (BPBI). Electronic databases were searched from inception to 15th February 2023 for studies reporting the accuracy of MRI (index test) compared to surgical exploration (reference standard) in detecting the target conditions of: root avulsion; any nerve abnormality; and pseudomeningocele (as a marker of root avulsion) in children with BPBI. Meta-analysis using a bivariate model was performed where data allowed. 8 studies met the inclusion criteria. In total, 116 children with BPBI were included. All included studies were at risk of bias. The mean sensitivity and mean specificity of MRI for detecting root avulsion was 68% (95% CI: 55%, 79%) and 89% (95% CI: 78%, 95%) respectively. Pseudomeningocele was not a reliable marker of avulsion. Data was too sparse to determine the diagnostic accuracy of MRI for any nerve abnormality. At present, surgical exploration should remain as the diagnostic modality of choice for BPBI due to the modest diagnostic accuracy of MRI in detecting root avulsion. The diagnostic accuracy of MRI needs to be close to 100% as the results may determine whether a child undergoes invasive surgery. Previous research regarding MRI in detecting BPBI is highly variable and prior to our study the overall diagnostic accuracy was unclear. Through conducting a systematic review and meta-analysis, we were able to reliably determine the overall sensitivity and specificity of MRI for detecting root avulsion.

MRI-based assessment of residual disease after neoadjuvant chemotherapy in pregnant women with cervical cancer

PurposeThis study explores the performance of MRI in detecting residual disease after platinum-based neoadjuvant chemotherapy (NACT) in pregnant cervical cancer (CC) patients, which would serve as a surrogate of treatment response. MethodsIn this retrospective single-centre study, consecutive pregnant cervical cancer patients treated with NACT and undergoing MRI examination before and at the end of the therapeutic protocol between 2010 and 2021 were included. Tumour maximum diameter and nodal status were evaluated in MRI at staging and after NACT. Patients exhibiting increased tumor burden post-NACT were excluded. On post-NACT the presence or absence of residual disease was recorded and the MRI diagnostic performance for assessing residual disease was calculated using histopathology at radical hysterectomy as the reference standard. ResultsThe study included 12 pregnant patients (median age 36 years, 27–42). At post-NACT MRI, residual disease was absent in 2/12 patients (16.7 %) while present in 10/12 (83.3 %). Histopathology was concordant in all patients without MRI residual disease and in 9/10 patients with MRI residual disease, while discordant in 1/10. MRI sensitivity, specificity, positive predictive value, negative predictive and accuracy for detecting residual disease were 100.0 % (95 %CI: 1.00, 1.00), 66.7 % (95 %CI: 0.13, 1.00), 90 % (95 %CI: 0.71, 1.00), 100 % (95 %CI: 1.00, 1.00), and 91.7 % (95 %CI: 0.76, 1.00) respectively (p = 0.045). ConclusionsThis study suggests that MRI has good diagnostic performance to detect residual disease after NACT in pregnant CC patients, and potentially assess response to treatment in this setting.

Detection of Apical Cancer with Novel Imaging Modalities to Predict Apical Margin Positivity in Robotic Assisted Radical Prostatectomy

ObjectivesTo evaluate margin positivity at apex utilizing preoperative magnetic resonance imaging [MRI], micro-ultrasound [MUS], prostate specific membrane antigen positron emission tomography PSMA PET] scan, biopsy location and intraoperative timing of deep venous complex [DVC] ligation during robot assisted radical prostatectomy [RARP]. MethodsInstitution review board approved retrospective study underwent RARP between November 2022 to March 2024. All patients underwent preoperative MRI, MUS and PSMA PET scan. Patients underwent RARP using either standard DVC [done prior apical dissection] ligation or delayed DVC [after prostate removal] technique. All patients underwent intra operative frozen section analysis by an experienced genitourinary pathologist. Descriptive statistics were performed. Data analyzed using R software version 4.3.3. ResultsTotal 619 prostate cancer patients underwent RARP. Of these, 365 men underwent RARP using delayed DVC ligation technique and 254 men using standard DVC ligation technique. There was no statically significant difference in 2 groups on demographic parameters, MRI, MUS and PSMA-PET scan features. Sensitivity of MRI, MUS, PSMA-PET and prostate biopsy for detection of apical positive margin were 66%, 81%, 81% and 73% respectively. Specificity of MRI, MUS, PSMA-PET and prostate biopsy for detection of apical positive margin were 45%, 14%, 16% and 30% respectively. When all modalities are used accumulatively, apical cancer was missed only in 1% of cases. ConclusionsWith proper preoperative understanding of apical lesion location, timing of DVC ligation [standard vs delayed] doesn't impact apical positive surgical margins. Combination of MRI, MUS, PSMA-PET and prostate biopsy reduce apical positive surgical margin rates significantly.

Magnetic Resonance Imaging MRI versus Color Doppler Ultrasound for Assessment of Placenta Accreta Spectrum Disorders

Abstract Background As placenta previa and placenta accreta are the two most common causes of postpartum hemorrhage, early and accurate diagnosis, preoperative assessment, and intraoperative management are crucial for a successful outcome. However, risk assessment of intraoperative massive hemorrhage in patients with placenta previa and accreta is challenging in clinical practice. Aim of the Work To compare the sensitivity and accuracy of MRI versus color Doppler US in the diagnosis of morbidly adherent placenta in women with placenta previa accreta spectrum. Subjects and Methods This was a cohort prospective study was done in cases was recruited from the pregnant women attending outpatient clinic or emergency department at Ain Shams University Maternity Hospital. The study was include 62 pregnant women. Results The final US results shows that from the 90 studied patients; 25 patients have no presence of accreta (37.8%) and 65 patients have presence of accreta (72.2%). The final MRI results shows that from the 90 studied patients; 35 patients have no presence of accreta (38.9%) and 55 patients have presence of accreta (61.1%). there was statistically significant increase in the percentage of patients with history of thyroidectomy and IUD removal laparoscopic in patients with placenta accreta (7.5% and 7.5%; respectively) than patients without placenta accreta (0.0% and 0.0%; respectively) with p-value = 0.049 and 0.049; respectively. there was statistically significant increase in the percentage of accuracy of MRI results (73.3%) than ultrasound results (58.9%). Conclusion Regarding to our results we concluded that ultrasound can detect patients with placenta accreta with sensitivity of 92.5%, specificity of 32.0% and overall accuracy of 58.9% while MRI can detect patients with placenta accreta with sensitivity of 100.0%, specificity of 52.0% and overall accuracy of 73.3%, there was statistically significant increase in the percentage of accuracy of MRI results (73.3%) than ultrasound results (58.9%) with p-value &amp;lt;0.001.

Survival implications of postoperative restricted diffusion in high-grade glioma and limitations of intraoperative MRI detection.

Here we assess whether the volume of cerebral ischemia induced during glioma surgery may negatively impact survival independently of neurological function. We also evaluate the sensitivity of intraoperative MRI (iMRI) in detecting cerebral ischemia during surgery. We retrospectively reviewed 361 cranial surgeries that used a 3 Tesla iMRI. 165 patients met all inclusion criteria and were included in the final analysis. Diffusion weighted imaging (DWI) obtained during iMRI was compared to postoperative DWI obtained within 7days of the operation in cases where no further resection occurred after the iMRI. 42 of 165 patients (25%) showed at least some evidence of restricted diffusion on postoperative (poMRI). 37 of these 42 (88%) cases lacked evidence of restricted diffusion on iMRI, meaning iMRI had a false-negative rate of 88% and a sensitivity of 12% in assessing the extent of ischemic brain after surgery. In high-grade gliomas, the volume of restricted diffusion on poMRI was predictive of overall survival, independent of new functional deficits acquired during surgery (p = 0.011). This study presents the largest case series to date analyzing the sensitivity of iMRI in detecting surgical ischemia. In high-grade gliomas, increased volume of ischemia correlated with worsening median overall survival (OS) irrespective of postoperative neurologic deficits. Future work will focus on improving intraoperative detection of ischemia during the hyperacute phase when interventions such as blood pressure modulation or direct application of vasodilator agents may be effective.

Bone assessment of the sacroiliac joint in ankylosing spondylitis: Comparison between computed tomography and zero echo time MRI

PurposeTo demonstrate the clinical applicability of zero echo time magnetic resonance imaging (ZTE MRI) in bone assessment of the sacroiliac joint in ankylosing spondylitis. MethodBetween January 2021 and November 2021, twenty-one ankylosing spondylitis patients underwent clinically indicated MRI including ZTE sequence, in addition, all patients underwent a CT scan covering the sacroiliac joints within 6 months of the MRI examination. The sensitivity, specificity, and accuracy of ZTE MRI were calculated using CT as the reference standard. Cohen’s κappa tests were applied to assess the agreement of positive imaging findings (including erosions, osteosclerosis, bony cystic changes, and joint space changes) between MRI and CT as well as the inter-reader agreement for the grading of sacroiliitis in AS patients. ResultsThere was no statistical significance between ZTE MRI and CT in detecting of ankylosing spondylitis(p＞0.05). The consistency of the diagnosis of positive imaging findings between ZTE MRI and CT was moderate to excellent (ranging from 0.611 to 0.889), and the consistency of the scores of positive imaging was good to excellent (ranging from 0.857 to 0.979). ConclusionsZTE MRI provides “CT-like” contrast for bony changes of the sacroiliac joint in ankylosing spondylitis and could simplify and reduce costs for some AS patients when both MRI and CT are typically required.

Usefulness of Combined Advanced Dynamic Contrast-Enhanced and Diffusion-Weighted MRI Over Ultrasonography in Differentiating Cancer From Benign Lesions in Dense Breasts.

Aim To evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) in characterizing suspicious lesions in dense breasts compared to ultrasonography (USG). Materials and methods Eighty-two consecutive female patients with suspicious lesions in dense breast parenchyma showing the American College of Radiology Breast Imaging Reporting And Data System (ACR BI-RADS) c/d composition on mammography underwent USG, where 63 lesions of 63 patients were suspicious. They underwent multiparametric MRI, followed by histopathological evaluation (HPE) of the lesions.Statistical analysis was done to calculate the sensitivity, specificity, and accuracy of USG and MRI in lesion characterization and the combined accuracy of DCE-MRI with DWI.The receiver operating characteristic (ROC) curve analysis provided the cut-off for the apparent diffusion coefficient (ADC) value. Results The sensitivity, specificity, and accuracy of USG were 91.7%, 63%, and 79.4%, respectively. Kinetic curve analysis on DCE-MRI showed a type I curve only in benign lesions. Malignant lesions predominantly showed a type III curve.The sensitivity, specificity, and accuracy of DCE-MRI were 95.8%, 78.5%, and 85.7%, respectively.The optimum cut-off ADC value was 1.05x10-3 mm2/s with sensitivity, specificity, and accuracy of 83.3 % each.The specificity and accuracy of combined DCE-MRI with DWI were 94.4% and 88.1%, respectively. Conclusion Advanced MRI, including a combination of DCE-MRI kinetics and DWI, would be more effective and accurate for lesion characterization in dense breasts and act as a superior problem-solving tool compared to USG in differentiating carcinoma from benign lesions.

What Predicts Complete Response to Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer?

Total neoadjuvant therapy in treatment of stage II-III rectal cancer involves administration of either induction or consolidation chemotherapy with chemoradiation before surgery. Total neoadjuvant therapy is associated with increased complete response rate, which is defined as the proportion of patients who either had pathological complete response after surgery or sustained clinical complete response at least for a year under surveillance. To identify the predictors of complete response to total neoadjuvant therapy and compare different diagnostic tools in predicting complete response. Retrospective cohort study. A single tertiary-care center. Stage II-III rectal cancer patients who were diagnosed between January 2015 and December 2021. Total neoadjuvant therapy. Complete response rate, predictors of complete response, sensitivity and specificity of sigmoidoscopy and MRI in predicting complete response. One hundred nineteen patients (mean age 56 [±11.3] years, 47 [39.5%] female, 100 [84%] stage III rectal cancer were included. Median tumor size was 5.1 (4-6.5) cm, 63 (52.9%) were low rectal tumors. Twenty-one (17.6%) patients had extramural vascular invasion, 62 (52.1%) had elevated carcinoembryonic antigen at baseline. One hundred eight (90.8%) patients received consolidation chemotherapy. After total neoadjuvant therapy, 88 (73.9%) out of 119 patients underwent surgery, of whom 20 (22.7%) had pathological complete response. Thirty-one (26.1%) patients underwent watch-and-wait, of whom 24 (77.4%) had sustained clinical complete response. Overall complete response rate was 37%. Low rectal tumors (OR 2.6 [95% CI, 1.1-5.9], p = 0.02) and absence of EMVI [OR 5.4 (95% CI, 1.2-25.1), p = 0.01] were predictors of complete response. In predicting complete response, sigmoidoscopy was more sensitive (76.0% vs. 62.5%) and specific (72.5% vs. 69.2%) than MRI. The specificity further increased when 2 techniques were combined (82.5%). Retrospective study. Complete response rate after total neoadjuvant therapy was 37%. Low rectal tumors and absence of extramural vascular invasion were predictors of complete response. Sigmoidoscopy was better in predicting incomplete response, whereas combination (MRI and sigmoidoscopy) was better in predicting complete response.

MRI accuracy for recurrence after partial gland ablation with HIFU for localized prostate cancer. A systematic review and meta-analysis.

Prostate cancer remains the most frequently diagnosed cancer among men. High-Intensity Focused Ultrasound (HIFU) has emerged as a thermal ablative technique for partial-gland-ablation (PGA), aiming to minimize collateral damage while maximizing tumor control. Monitoring after HIFU PGA relies on serial PSA testing, multiparametric-MRI, and biopsies. The diagnostic accuracy of MRI for clinically-significant cancer(csPCa) recurrence is challenging. This systematic review and meta-analysis aim to evaluate the accuracy of MRI in detecting early recurrence of localized prostate cancer following HIFU PGA. Adhering to PRISMA guidelines, a comprehensive literature search was conducted until May 8th 2024 using MEDLINE and Scopus. The inclusion criteria encompassed randomized controlled trials and cohort studies involving men diagnosed with localized prostate cancer who had as primary treatment HIFU PGA. The primary outcome measures included the sensitivity, specificity, positive-predictive value (PPV), and negative-predictive value (NPV) of MRI for csPCa(ISUP ≥ 2) based on biopsy results. We pooled data from studies with sufficient csPCa and csPCa-free patients (≥5) post HIFU for statistical analysis. Fifteen studies meet the inclusion criteria, encompassing 1093 patients and 12 studies were eligible for meta-analysis. MRI sensitivity in detecting clinically-significant prostate cancer (csPCa) recurrence post HIFU PGA varied widely (0-89%), with a pooled sensitivity of 0.52 (95% CI:0.36-0.68). Specificity ranged from 44% to 100%, with a pooled specificity of 0.81 (95% CI:0.68-0.91). The pooled NPV was 0.82 (95% CI:0.72-0.90), and the pooled PPV was 0.50 (95% CI:0.35-0.65). Three studies reported in-field diagnostic performance with sensitivities ranging from 0.42 to 0.80 and specificities from 0.45 to 0.97. MRI accuracy for clinically-significant recurrence after partial gland ablation with HIFU for localized prostate cancer shows low diagnostic performance in the treated lobe with pooled sensitivity of 0.52 (95% CI:0.36-0.68) and specificity of 0.81 (95% CI:0.68-0.91). Limits of this review include the low number of studies reporting about site of recurrence in or out of the treated lobe.

Ultrathin Gd-Oxide Nanosheet as Ultrasensitive Companion Diagnostic Tool for MR Imaging and Therapy of Submillimeter Microhepatocellular Carcinoma.

Early stage hepatocellular carcinoma (HCC) presents a formidable challenge in clinical settings due to its asymptomatic progression and the limitations of current imaging techniques in detecting micro-HCC lesions. Addressing this critical issue, we introduce a novel ultrathin gadolinium-oxide (Gd-oxide) nanosheet-based platform with heightened sensitivity for high-field MRI and as a therapeutic agent for HCC. Synthesized via a digestive ripening process, these Gd-oxide nanosheets exhibit an exceptional acid-responsive profile. The integration of the ultrathin Gd-oxide with an acid-responsive polymer creates an ultrasensitive high-field MRI probe, enabling the visualization of submillimeter-sized tumors with superior sensitivity. Our research underscores the ultrasensitive probe's efficacy in the treatment of orthotopic HCC. Notably, the ultrasensitive probe functions dually as a companion diagnostic tool, facilitating simultaneous imaging and therapy with real-time treatment monitoring capabilities. In conclusion, this study showcases an innovative companion diagnostic tool that holds promise for the early detection and effective treatment of micro-HCC.

Automated Breast Ultrasound for Evaluating Response to Neoadjuvant Therapy: A Comparison with Magnetic Resonance Imaging.

Background: Neoadjuvant chemotherapy (NAC) is currently used for treating breast cancer in selected cases. Our study aims to evaluate the role of automated breast ultrasound (ABUS) in the assessment of response to NAC and compare the ABUS results with MRI. Methods: A total of 52 consecutive patients were included in this study. ABUS and MRI sensitivity (SE), specificity (SP), diagnostic accuracy (DA), positive predictive value (PPV), and negative predictive value (NPV) were calculated and represented using Area Under ROC Curve (ROC) analysis, searching for any significant difference (p < 0.05). The McNemar test was used searching for any significant difference in terms of sensitivity by comparing the ABUS and MRI results. The inter-observer agreement between the readers in evaluating the response to NAC for both MRI and ABUS was calculated using Cohen's kappa k coefficient. Results: A total of 35 cases of complete response and 17 cases of persistent disease were found. MRI showed SE, SP, DA, PPV, and NPV values of 100%, 88%, 92%, 81%, and 100%, respectively, with an AUC value of 0.943 (p < 0.0001). ABUS showed SE, SP, DA, PPV, and NPV values of 88%, 94%, 92%, 89%, and 94%, respectively, with an AUC of 0.913 (p < 0.0001). The McNemar test revealed no significant difference (p = 0.1250). The inter-observer agreement between the two readers in evaluating the response to NAC for MRI and ABUS was, respectively, 0.88 and 0.89. Conclusions: Automatic breast ultrasound represents a new accurate, tri-dimensional and operator-independent tool for evaluating patients referred to NAC.

MRI in the prenatal genetic diagnosis and intrauterine treatment of fetal congenital cystic adenoma of the lung

ObjectiveTo investigate the value of magnetic resonance examination technique for prenatal genetic diagnosis and clinical intrauterine treatment of fetal congenital cystic adenoma (CCAM) of the lung.MethodsA retrospective analysis was conducted on 108 pregnant women admitted to a certain hospital from January 2016 to January 2022 for pre natal examination and consultation on eugenics. The selected pregnant women were aged 20–40 and had a gestational age of 17–36 weeks. Ultrasound and MRI examinations were performed on 108 pregnant women who met the inclusion criteria. Follow-up and investigation were conducted on the fetus after being diagnosed with CCAM. To analyze the results of prenatal genetic diagnosis, chromosome microarray analysis (CMA) was used to analyze samples with pathogenic Copy Number Variants (CNV) and identify pathogenic genes. Finally, the imaging diagnosis results obtained through statistical software were analyzed, and the correlation between pathogenic genes and CCAM, as well as the clinical application value of MRI in fetal intrauterine treatment was explored.ResultsAmong all cases, 68 fetuses were diagnosed with CCAM through ultrasound examination; 71 fetuses were diagnosed with CCAM through MRI examination. A total of 74 samples were confirmed as CCAM by autopsy and neonatal CT. The sensitivity, specificity, and accuracy of MRI in diagnosing fetal congenital CCAM were higher than those of ultrasound examination. The expression of CCAM was positively correlated with DUSP22, PRSS1, and SHOX, with all R values greater than 0.8. The clinical decision curve showed that when the probability of fetal CCAM was less than 0.03, the prenatal genetic diagnostic model of MRI was not applicable; But when the probability of fetal CCAM was higher than 0.05, the auxiliary intrauterine treatment effect that MRI diagnostic methods achieved was significantly better than conventional diagnosis.ConclusionMRI is significantly better than ultrasound in the diagnosis of CCAM, which can effectively improve the sensitivity of diagnosis and provide accurate information for the eugenics of pregnant women, and has high clinical application value.

Diagnostic Value of T2-MRI in Incidental Cystic Renal Masses on Lumbar Spine MRI

Background: Cystic renal masses (CRM) are found incidentally in many patients undergoing lumbar MRI. cysts. Objectives: The present study aimed to determine the diagnostic value of T2-weighted imaging features of CRM on lumbar spine MRI and their reliability in differentiating complex renal lesions from simple Methods: All lumbar MRIs performed between 2019 and 2021 were included in this prospective study. Patients with simple cysts on MRI underwent a renal ultrasound by an expert radiologist. Patients with complex or suspicious cysts, based on sonographic characteristics, were subjected to a CT scan with contrast. For complex cysts identified on MRI, patients underwent a CT scan with contrast without first undergoing an ultrasound examination. Finally, the sensitivity, specificity, and positive and negative predictive values of T2 lumbar MRI images were calculated to determine the nature of the cysts. Results: A total of 2,789 lumbar MRIs were performed during the study period. Of these, 169 cases (6.05%) were reported to have incidental kidney cysts. No significant differences were found between the age and sex of the patients. The size of the cysts differed significantly between complex and simple cysts. The sensitivity, specificity, and positive and negative predictive values of MRI in determining the nature of the cyst were calculated to be 100%, 98%, 83%, and 100%, respectively. Conclusions: The results of the present study showed that further examinations using ultrasound and CT scans in patients with simple renal cysts on lumbar MRI are not recommended, which can significantly reduce health care costs.

Improvement of MRS at ultra-high field using a wireless RF array.

We aim to assess a straightforward technique to enhance spectral quality in the brain, particularly in the cerebellum, during 7 T MRI scans. This is achieved through a wireless RF array insert designed to mitigate signal dropouts caused by the limited transmit field efficiency in the inferior part of the brain. We recently developed a wireless RF array to improve MRI and 1H-MRS at 7 T by augmenting signal via inductive coupling between the wireless RF array and the MRI coil. In vivo experiments on a Siemens 7 T whole-body human scanner with a Nova 1Tx/32Rx head coil quantified the impact of the dorsal cervical array in improving signal in the posterior fossa, including the cerebellum, where the transmit efficiency of the coil is inherently low. The 1H-MRS experimental protocol consisted of paired acquisition of data sets, both with and without the RF array, using the semi-LASER and SASSI sequences. The overall results indicate that the localized 1H-MRS is improved significantly in the presence of the array. Comparison of in vivo 1H-MRS plots in the presence versus absence of the array demonstrated an average SNR enhancement of a factor of 2.2. LCModel analysis reported reduced Cramér-Rao lower bounds, indicating more confident fits. This wireless RF array can significantly increase detection sensitivity. It may reduce the RF transmission power and data acquisition time for 1H-MRS and MRI applications, specifically at 7 T, where 1H-MRS requires a high-power RF pulse. The array could provide a cost-effective and efficient solution to improve detection sensitivity for human 1H-MRS and MRI in the regions with lower transmit efficiency.